Control valve construction



Oct. 5, 1965 D. s. STRADER CONTROL VALVE CONSTRUCTION Filed June 21, 1962 United States Patent 3,209,781 CONTROL VALVE CONSTRUQTKON Don S. Strader, Mount Prospect, 111., assignor to The Frank G. Hough (10., a corporation of Illinois li iied June 21, 1962, Ser. No. 204,152 4 Claims. (Cl. 137596.2)

This invention relates to a control valve for a doubleacting fluid pressure actuator, and more particularly to a control valve construction wherein a check valve is employed to provide movement of the fluid actuator in one of two directions to downwardly move a heavy member only when suflicient actuating pressure fluid appears in the fluid actuator.

It is an object of this invention to provide a control valve wherein a check valve positioned at one end of a chamber that is connected at the other end to one end of the valve spool chamber permits movement in one of two directions of the double-acting fluid actuator only when sufficient actuating fluid pressure appears therein to move a heavy member such as a boom arm.

Another object of this invention is to provide a control valve wherein a resilient valve means positioned at one end of a chamber that is connected at the other end of the valve spool chamber permits only downward movement of the double-acting fluid actuator connected at its upper end to a heavy member such as a boom arm when suflicient actuating fluid pressure to downwardly move the boom arm appears in the fluid actuator to open the control valve resilient valve means in the chamber through actuated fluid pressure in the chamber to thereby power down the boom arm.

Still another object of this invention is to provide a control valve including a valve spool and spool chamber wherein a resilient valve means positioned at one end of a chamber that is connected at the other end to the valve spool chamber wherein the resilient valve means permits pressure fluid flow in only one direction and only at a predetermined value such that movement in one of two directions of a double-acting fluid actuator to downwardly move a heavy member such as a boom arm occurs only when actuating pressure fluid from the control valve appears at one end in the double-acting fluid actuator to thereby cause actuated pressure fluid at the other end thereof and in the resilient valve chamber to be of the predetermined value to thereby open the resilient valve means and to thereby power down the boom arm.

Another object of the present invention is to provide a control valve including a valve spool and a spool chamber wherein a valve means positioned at one end of another chamber that is connected at its other end to the valve spool chamber wherein the valve means permits pressure fluid flow in only one direction and only at a predetermined pressure value in connection with the operation of a hydraulic ram in one of two operating directions. Further the valve means and its chamber do not interfere with the operation of other valve means within the control valve such as anticavitation valves, circuit relief valves and loading valves; these specifically mentioned other valve means are known to those skilled in the art.

Other objects and features of the invention will be apparent upon a perusal of the following specification and drawings, of which: the drawing is a cross-sectional view, in part, of the control valve illustrating the important parts of the subject invention.

The present embodiment is the preferred embodiment, but it is to be understood that changes can be made in the present embodiment by one skilled in the art Without departing from the spirit and scope of the present inven' tion.

For a detailed description of the subject invention conice tinued reference to the drawing is now made. Control valve 10 comprises a housing 11 shown in cross-section detail in the drawing and wherein control valve 11) further comprises valve spool 12 slidable in chamber 13 and another identical valve spool 14 slidable in chamber 15. A reservoir 16 and pump 17 are connected to an inlet port 18 through conduit not indicated; similarly, the outlet port 19 is connected to the reservoir 16 through a return conduit not indicated. A relief valve is generally in dicated by the reference number 21 and constructed according to the general construction known to those skilled in the art. In the drawing, chambers 22, 23 and 24 are in fluid communication with each other through the valve spool bores or chambers 13 and 15 and therefore provide free fluid communication from inlet port 18 to outlet port 19.

Valve spool chamber 15 further includes spaced-apart annular grooves 25 and 26 which include fluid actuator ports each separately connectable to fluid actuator conduits 27 and 23. For the purpose of simplicity fluid actuator ports have not been shown in detail but it is to be understood that these ports are of conventional construction. The other end of conduits 27 and 281 are connected to opposite ends of a fluid actuator, namely, a hydraulic ram 29 fastened at its lower end 30 to a tractor loader 34 of general construction and at the other end of the double acting hydraulic ram 29, namely, its rod end 31 intermediate the ends of the boom arm 32 supporting at the outer end thereof a shovel 33. A duplicate boom arm 32 and hydraulic ram 29 are provided on the other side of the tractor loader, not shown, for purposes of simplicity. To understand further if necessary the details of the tractor loader 34 reference is drawn to the Patent 2,986,292 issued to Kampert et al. entitled, Bucket Operating Means for Tractor Loaders granted on May 30, 1961. It is to be further understood that the connection of conduits 27 and 28 in the manner shown to ram 29 of tractor loader 34 and the connection of the piston rod member of ram 29 intermediate the ends of boom arm 32 is not intended to be the sole application of the subject invention but that the subject invention could readily be adapted to other applications.

Valve spool 14 is provided with one or more hollow bores connected to spool surface by means of a plurality of transverse openings located successively along the valve spool. One of the outermost lands 39 includes three transverse openings 35 spaced below three separate transverse openings 36. The other outermost land 41 includes three separate transverse openings 37 spaced below three separate transverse openings 38. Openings 35 and 36 in outermost land 39 and openings 37 and 38 in outermost land 41 are interconnected by an internal passageway connecting opposite openings shown by invisible lines not indicated. Between outermost lands 39 and 41 of valve spool 14 is a centermost annular land 42 connected to the outermost lands 3? and 41 through reduced portions 43 and 44 each providing an annular groove. Valve spool 12 is of identical construction as valve spool 14 but has not been explained in detail since it does not perform an important part of the subject invention.

A chamber 45 is connected at one end to valve spool chamber 15. At the other end of chamber 45 a check valve 46 is positioned against a seat in the opening 48 by a spring 47. The purpose of check valve 46 is to prevent pressure fluid flow from outlet port chamber 24- into chamber 45 but to provide pressure fluid flow from chamber 45 into outlet port chamber 24 only at a pressure of a predetermined value. Therefore, check valve spring should be selected to have a seating force such that the predetermined pressure value of the pressure fluid in chamber 45 should substantially equal the downward acting force of a heavy member or boom arm 32 acting on connected piston rod member of the double-acting hydraulic ram 29. Thus spring 47 should be selected to have a seating force that substantially equals the eflective weight or downward acting force of a heavy member acting on the piston rod or actuating means of the hydraulic ram 29.

Valve spool 14 is slidable in the valve chamber 15 by means of a manual operator linkage or other suitable linkage connected to the reduced portion at the outer end of outermost land 41. Although the operator linkage is not shown in the drawing, it is to be understood that it may be of any suitable construction known in the art. In the drawing valve spool 14 is shown in the neutral position such that flow of pressure fluid from inlet port is communicated from chamber 23 into outlet port chamber 24 through reduced portions 43 and 44 and bore or chamber 15. In the neutral position no flow of pressure fluid is communicated to fluid actuator conduits 27 and 28. Movement of the valve spool 14 upwardly in the drawing or the first position, pressure fluid in chamber 23 flows through openings 36, openings 35 through internal passageways, not indicated, annular groove 25, conduit 27 and to the upper end or rod end of double-acting hydraulic ram 2?. Check valve chamber 45 is in fluid communication with the lower end of hydraulic ram through conduit 28, annular groove 26, openings 37, openings 38 through internal passageways, not indicated, and then to chamber 45. In the first position of valve spool 14 annular land 42 blocks fluid communication between the upper end of chamber 23 and outlet chamber 24 in the drawing. Outermost land 39 blocks fluid communication from the lower end of chamber 23 to the outlet chamber 24. The valve spool 14 can be moved to the lower or second position in which the lower end of hydraulic ram 29 is in fluid communication \m'th chamber 23 through conduit 28, annular groove 26, openings 38 and openings 37 to chamber 23. The upper or rod end of hydraulic ram 29 is in fluid communication with outlet chamber 24 through conduit 27, annular groove 25, openings 36 and openings to chamber 24. With the valve spool in the second position, the centermost annular land 42 blocks otf fluid communication from the lower portion of chamber 23 in the drawing to outlet chamber 24 while the outermost land 41 in cooperation with valve chamber 15 blocks off fluid communication from the upper portion of chamber 23 in the drawing to outlet chamber 24. It is to be understood that the valve spool 14 may be formed of any other construction known in the art other than that described without departing from the spirit and scope of the subject invention.

Having described the detailed description, operation of the subject invention will be set forth. When the valve spool 14 is in the neutral position as shown in the drawing pressure fluid flows from pump 17 and inlet port 18 to outlet port 19 through chamber 22, chamber 23, chamber 24 and then to outlet port 19. In the neutral position the double acting ram 29 receives no pressure fluid from pump 17 but remains hydraulically locked in the position as shown in the drawing. If the valve spool 14 is moved to the first position actuating pressure fluid is in communication from inlet chamber 23, conduit 27 to rod end of ram 29 while actuated pressure fluid in piston end of ram 29 is in communication with chamber 45 through conduit 28. However, no pressure fluid will flow to outlet port 1? unless the actuating fluid conducted through conduit 27 is of sufficient pressure with valve spool 14 in the first position to cause the actuated fluid in the piston end of ram 29 in chamber 45 to be above the selected seating force of check valve spring 47. As aforementioned, the seating force of the spring 47 is substantially equal to the effective weight of boom arm 32 acting on connected piston rod member of arm 2?. Then when the actuated pressure fluid in chamber 45 exceeds the seating force of spring 4-7 the actuated pressure fluid flows from chamber 45 to outlet port 19 to power down the boom 32 from the position shown in the drawing. Thus check valve 46 prevents downward movement of boom 32, if the pressure fluid in chamber 45 is below the predetermined pressure value. If the valve spool 14 is moved to the second position pressure fluid from inlet port 18 is directed to the piston end of the ram 29 to raise the boom arm 32 through pressure fluid flow from chamber 23, openings 37, openings 33, annular groove 26, conduit 28 and then to the piston end of ram 28. Return pressure fluid in the rod end of ram 29 flows from conduit 27, annular groove 25, opening 36, openings 35 and then to out let port 19 to reservoir 16.

Having described the invention what is considered new and desired to be protected by Letters Patent is:

1. A fluid control valve for controlling a hydraulic system including a fluid source and a fluid operated means, comprising: a housing containing inlet and outlet ports said inlet port connected to the fluid source, a first chamber in said housing, a valve element having means for directing fluid flow slidable in said first chamber and selectively positionable therein, a pair of spaced-apart ports in said housing connectable to said first chamber and further connectable to the fluid operated means so that entrance of pressure fluid in one port of said pair of ports moves the fluid operated means in one direction and entrance of pressure fluid in the other port of said pair of ports moves the fluid operated means in another direction, a second chamber in said housing connectable at one end to said first chamber, a resilient valve means at the other end of said second chamber to prevent fluid flow from said outlet port to said second chamber, said resilient valve means being operable to open position above a predetermined value to provide flow of pressure fluid from said second chamber to said outlet port, said slidable valve element during a first selective position directing pressure fluid from said inlet port to said outlet port, said slidable valve element during a second selective position directing pressure fluid from said inlet port to the fluid operated means through one port of said pair of ports and directing pressure fluid from the fluid operated means through another port of said pair of ports to said second chamber, the fluid operated means being movable in one direction with said valve element in said second position when said fluid pressure in said second chamber is above said predetermined value of said resilient valve means thereby providing pressure fluid flow to said outlet port, said slidable valve element during a third selective position directing pressure fluid from said inlet port to said another port of said pair of ports and said one port of said pair of ports to receive pressure fluid from fluid operated means to be directed to said first chamber and said outlet port whereby the fluid responsive means is movable in said another direction.

2. A fluid control valve for controlling a hydraulic system including a fluid source and a fluid responsive means, comprising a housing containing inlet and outlet ports said inlet port connected to the fluid source, a first chamber in said housing, a valve element having means for directing fluid flow slidable in said first chamber and selectively positionable therein, a pair of spacedapart ports in said housing connectable to said first chamber and further connected to the fluid responsive means so that entrance of pressure fluid in one port of said pair of ports moves the fluid responsive means in one direction and entrance of pressure fluid in the other port of said pair of ports moves the fluid responsive means in another direction, a second chamber in said housing connectable at one end to said first chamber, a resilient valve means at the other end of said second chamber to prevent fluid flow from said outlet port to said second chamber, said resilient valve means being operable to open position above a predetermined value to provide flow of pressure fluid from said second chamber to said outlet port, said slidable valve element during a first selective position directing pressure fluid from said inlet port to the fluid responsive means through i one port of said pair of ports and directing pressure fluid from the fluid responsive means through another port of said pair of ports to said second chamber, the fluid responsive means being movable in one direction with said valve element in said first position when said fluid pressure in said second chamber is above said predetermined value of said resilient valve means thereby providing pressure fluid flow to said outlet port, said slidable valve element during a second selective position directing pressure fluid from said inlet port to said another port of said pair of ports and said one port of said pair of ports to receive pressure fluid from the fluid responsive means to be directed to said first chamber and said outlet port whereby the fluid responsive means is movable in said other direction.

3. A fluid control valve for controlling a hydraulic system including a fluid source and a fluid responsive means, comprising a housing containing inlet and outlet ports, said inlet port connected to the fluid source, a first chamber in said housing, a valve element having means for directing fluid flow slidable in said first chamber and selectively positionable therein, a pair of spacedapart ports in said housing connectable to said first chamber and further connectable to the fluid responsive means so that entrance of pressure fluid in one port of said pair of ports moves the fluid responsive means in one direction and entrance of pressure fluid in the other port of said pair of ports moves the fluid responsive means in another direction, a second chamber in said housing connectable at one end to said first chamber, a resilient valve means at the other end of said second chamber to prevent fluid flow from said outlet port to said second chamber, said resilient valve means being operable to open position above a predetermined value to provide flow of pressure fluid from said second chamber to said outlet port, said slidable valve element during a selective position directing fluid from said inlet port to the fluid responsive means through one port of said pair of ports and directing pressure fluid from the fluid responsive means through another port of said pair of ports to said second chamber, the fluid responsive means being movable in one direction with said valve element in said selective position when said fluid pressure in said second chamber is above said predetermined value of said resilient valve means thereby providing pressure fluid flow to said outlet port.

4. A fluid control valve for controlling a hydraulic system having a fluid source and a fluid responsive means, comprising a housing containing inlet and outlet ports said inlet port connected to the fluid source, a first chamber in said housing, a valve element slidable in said first chamber and selectively positionable therein, a pair of spaced-apart ports in said housing connectable to said first chamber and further connectable one port to each end of the fluid responsive means, a second chamber in said housing connectable at one end to said first chamber, said second chamber having a resilient valve means connected at the other end thereof to prevent fluid flow from said out let port, said resilient valve means being operable to open position above predetermined value to provide flow of pressure fluid from said second chamber to said outlet port, said slidable valve element being selectively positionable to direct pressure fluid from said inlet port to the fluid responsive means through one port of said pair of ports to move the fluid responsive means in one of two directions when the fluid pressure in said second chamber is above said predetermined value relative to said resilient valve means.

References Cited by the Examiner UNITED STATES PATENTS 2,263,421 11/41 Harrington 1376l2.1 2,362,339 11/44 Armington 137---596.18 2,384,760 9/45 Matulionis 91-443 2,448,532 9/48 Kirkham 137--596.12 XR 2,949,097 8/60 Vander Kay 137--596.12 2,980,135 4/61 Tennis 137-59612 2,986,166 5/61 Hoen 137596.13 3,000,397 9/61 Schmiel 137596.13

M. CARY NELSON, Primary Examiner.

MILTON KAUFMAN, Examiner. 

1. A FLUID CONTROL VALVE FOR CONTROLLING A HYDRAULIC SYSTEM INCLUDING A FLUID SOURCE AND A FLUID OPERATED MEANS, COMPRISING: A HOUSING CONTAINING INLET AND OUTLET PORTS SAID INLET PORT CONNECTED TO THE FLUID SOURCE, A FIRST CHAMBER IN SAID HOUSING, A VALVE ELEMENT HAVING MEANS FOR DIRECTING FLUID FLOW SLIDABLE IN SAID FIRST CHAMBER AND SELECTIVELY POSITIONABLE THEREIN, A PAIR OF SPACED-APART PORTS IN SAID HOUSING CONNECTABLE TO SAID FIRST CHAMBER AND FURTHER CONNECTABLE TO THE FLUID OPERATED MEANS SO THAT ENTRANCE OF PRESSURE FLUID IN ONE PORT OF SAID PAIR OF PORTS MOVES THE FLUID OPERATED MEANS IN ONE DIRECTION AND ENTRACE OF PRESSURE FLUID IN THE OTHER PORT OF SAID PAIR OF PORT MOVES THE FLUID OPERATED MEANS IN ANOTHER DIRECTION, A SECOND CHAMBER IN SAID HOUSING CONNECTABLE AT ONE END TO SAID FIRST CHAMBER, A RESILIENT VALVE MEANS AT THE OTHER END OF SAID SECOND CHAMBER TO PREVENT FLUID FLOW FROM SAID OUTLET PORT TO SAID SECOND CHAMBER, SAID RESILIENT VALVE MEANS BEING OPERABLE TO OPEN POSITION ABOVE A PREDETERMINED VALUE TO PROVIDE FLOW OF PRESSURE FLUID FROM SAID SECOND CHAMBER TO SAID OUTLET PORT, SAID SLIDABLE VALVE ELEMENT DURING A FIRST SELECTIVE POSITION DIRECTING PRESSURE FLUID FROM SAID INLET PORT TO SAID OUTLET PORT, SAID SLIDABLE VALVE ELEMENT DURING A SECOND SELECTIVE POSITION DIRECTING PRESSURE FLUID FROM SAID INLET PORT TO THE FLUID OPERATED MEANS THROUGH ONE PORT OF SAID PAIR OF PORTS AND DIRECTING PRESSURE FLUID FROM THE FLUID OPERATED MEANS THROUGH ANOTHER PORT OF SAID PAIR 